On the Development of Turbomachine Blade Aerodynamic Design System

Abstract

A turbomachine blade aerodynamic design process is proposed to design turbomachine blades. The design system, including a global optimization of through flow for whole machine and a local optimization of the airfoil design and airfoil section, stacks up. The airfoil generator code employs Bezier polynomial curves to produce smooth airfoil shapes. A meanline program combined with an optimizer was used to perform the global optimization. In the airfoil section design, for fast calculations of the airfoil pressure distributions a discrete vortex method is developed. A novel Navier-Stokes (N-S) solver is developed for further examination of the airfoil performance for final section design. The N-S code is used to obtain the blade-to-blade quasi-three-dimensional, turbulent, and viscous flow characteristics. The time-dependent N-S equations are discretized and integrated in a coupled manner based on a finite-volume formulation, as well as a flux-difference splitting. The flux-difference splitting method enables us to compute with a rapid convergence. The present N-S code can handle computations of both subsonic and supersonic flows and can be connected to an external optimizer code with the airfoil generator. After optimized airfoil was designed, a three-dimensional code was used for final tuning of the design.